Prepositions – Time English Usage Example on days of the week on Monday in months / seasons time of day year after a certain period of time (when?) in August / in winter in the morning in 2006 in an hour at for night for weekend a certain point of time (when?) at night at the weekend at half past nine since from a certain point of time (past till now) since 1980 for over a certain period of time (past till now) for 2 years ago a certain time in the past 2 years ago before earlier than a certain point of time before 2004 to telling the time ten to six (5:50) past telling the time ten past six (6:10) to / till / until marking the beginning and end of a period of time from Monday to/till Friday till / until